The goal of the proposed research is to prove the principle that radiation inducible neoantigens can be targeted with therapeutic antibodies. Radiation induction of neoantigens in cancer occurs through the physiologic response of cancer cells to DNA strand breaks and oxidative stress. These antigens are discovered in our laboratory through the use of phage displayed technology and subtractive immunization which has led to over 700 monoclonal antibodies (Platform Technology and Pipeline). This platform technology has discovered several lead mAb's to distinct radiation inducible proteins. Monoclonal antibodies are prioritized by near infrared imaging of human cancer xenografts in nude mice based upon cancer specific binding and pharmacokinetics. The lead antibodies bind to radiation inducible antigens TIP-1, GRP78 and CRT. The monoclonal antibody to TIP-1 will be studied first because it demonstrates cancer specific and prolonged binding in human cancers in mice. We studied the biodistribution and pharmacokinetics of labeled antibody and mouse models of cancer. This mAb to radiation inducible TIP-1 and GRP78 are prioritized because 15 of 16 human cancers in nude mice show cancer specific binding. Moreover, TIP-1 and GRP78 remain tethered to the irradiated cell and antibodies bind specifically to the cancer for several days. In the proposed study, radiolabeled anti-TIP-1 and anti-GRP78 antibodies will be administered to patients receiving radiotherapy. The exploratory IND guidelines will allow us to conduct proof of concept in clinical trials in cancer patients receiving radiotherapy for these incurable cancers. Patients who are referred for radiotherapy will be stratified during accrual according to disease type. Cu64 - labeled antibody will be administered intravenously immediately after radiotherapy. Patients will be imaged by PET scans at 2, and 24 hours. If PET scans show cancer specific binding in 2 or more out of 6 patients in each disease type, then the antibody will be humanized for planned future Phase I and II clinical trials. PUBLIC HEALTH RELEVANCE: Poor prognostic cancers that are treated with radiation therapy include cancers of the lung, pancreas, esophagus, breast, brain and rectum. These cancers show radiation-induced expression of new antigens on the surface of neoplastic cells. We developed antibodies to the inducible neoantigens. We will now study the pharmacokinetics and biodistribution of these antibodies in patients receiving radiotherapy.